For instance: I always though the optional Move "Things are tough" was a little off.
It is of note that Vincent says right in the AW rulebook that that "move" was included because playtest groups wanted it, but that it's not recommended because it doesn't add anything other than hassle. Apocalypse World makes no claim to model degree of difficulty in any way other than through the fiction, so that particular move is a spectacularly bad example - it's not central to how the game functions.
Pretty much the entire point of that 'optional' move is that it is terrible and nobody should use it. It's like a way to tell if somebody has understood the game, or if they are still struggling to understand how fiction-first play works.
I absolutely agree. And, I have yet to find a justifiable reason to use this "move" in any of my games. My point was that "logically" it fit the established mechanics better as a tag rather than "move":
To me, it made more since to stick these mechanics in as optional tags: Stupid-easy (+3), Easy (+1), Difficult (-1), Crazy-Difficult (-3). At least that's how I do it in my AW Hack.
If you play the game with the situational fiction in mind, you don't need these tags at all.